In assisted reproductive technology (ART), only mature eggs that reach metaphase-II stage (MII) are capable of becoming fertilized and developing as embryos, while not-fully-mature oocytes that do not attain this stage must typically be discarded. In some patients, most or all oocytes recovered for ART treatments display a maturation arrest, leading to very poor fertilization rates (Levran et al 2002). What is needed, therefore, are methods and compositions that allow immature oocytes, arrested in pre-MII stage, to be reactivated and proceed to the MII stage.